Optical fibers are generally constructed with a glass core of approximately 125 micron thickness, and are used to transmit signals across the fiber in the form of light or light pulses. Currently, optical fibers are typically produced with a UV-curable coating, such as a UV acrylate material. This primary buffer is applied in the fiber drawing process in a drawing tower. The UV curable coating increases the overall size of the outside diameter of the fiber to approximately 250 microns. UV coated fibers are typically individually inked with different colors for identification. The fibers may then placed into a ribbon matrix or otherwise bundled together and placed into plastic tubing for use in outdoor applications.
For indoor applications it is required that the fibers meet certain fireproofing standards. However, the standard UV curable coating described above, is highly flammable. To meet the fireproofing standards, a second fire retardant PVC-jacket is extruded onto the base UV coated optical fiber, forming what is know as tight buffer fibers. These tight buffer fibers are typically in the thickness range of 900 microns and bundled and jacketed for use in mostly indoor applications and some outdoor applications as well.
However, there is no current solution for indoor use fiber cable arrangements that meet the necessary fire standards, can be handled regularly for splicing operations and are also capable of standing alone use without the need for a secondary bundling, such as insertion within a tube or other external binding.